Turtles in Heat
by le error
Summary: Mpreg - Donnie and Leo are in their mating seasons. Donnie, unfortunately, has to house ripe unfertilized eggs for the entire season. Leo has difficulty resisting at such an opportunity and Donnie can't control himself.


The worst part about spring wasn't even the outdoor allergies.

The whole season was a strict dry spell for Donnie and Leo. However, spring had a little funny way of always making this difficult for them. Mating season was damn near impossible to resist even for someone like Leonardo. His urges were intense whenever he was near his mate. Donnie's scent was like a large broadcast to him, screaming into his brain to fuck him and breed him. Donnie was close to the opposite of Leo. He still battled in a sex heat but every spring he had to deal with a fresh unfertilized clutch of eggs. They weren't too large, he had taken an ultrasound on himself to make sure they weren't actual tiny turtles inside of him. All the eggs were just unfertilized but ripe at any moment. Donnie had to carry around this load in his gut, a tight round belly that wasn't too overbearing, but still an annoyance. It was enough to suppress his sexual frenzy. Just imagining birthing out six or nine tiny turtles was major turn off. He wasn't ready for that sort of thing and neither was Leo. During mating season, there was hardly a care.

Leo's primal instincts kicked in whenever he saw Donnie's cute belly. A fresh clutch, eggs that needed to be properly fertilized and right for his taking. The logic part of himself told him no. He would eventually settled with masturbating in his room or a cold shower. It was hard not touching Donnie since he seemed to glow during his cycle. His scent was alluring, so wonderful and hard to resist. _Ugh, there's no way I can keep this up. _

Touching himself was getting boring, even though it did get the job done, he needed Donnie so much. He thought of every idea in the book even going to human condoms but he wasn't sure if those would work. Donnie couldn't top him cause it would be uncomfortable for him with his large belly. Leo smacked his cheek, trying to get himself to calm down and get a hold of himself. He could wait. Yes. After spring and both of their cycles were over with, Leo was going to make Donnie pay for making him wait so long.

His calmness was short lived once he saw Donnie in the kitchen. He was bent over the sink, his ass and his tail out like nothing. His tongue poked out in deep concentration as he tightened the screws to bolt down the sink. Leo forced himself to look away from Donnie's ass but his face was already bright red. Donnie moved away from the sink and sighed deeply. "There." He mumbled to himself. He still wasn't aware of Leo being in the same room as him.

Leo coughed lightly into his hand, making Donnie alert of his presence. "What are you doing?" He asked.

Donnie leaned back quickly and turned around. "O-oh. Just fixing the knob. It's been loose for a while now. Uh.."

Leo stepped closer to Donnie, his hand gripped tightly at the edge of the table and leaned against it. Leo's eyes lingered on Donnie's swollen stomach and a little lower.

"Why are here?" Donnie asked.

"I miss you." Leo replied bluntly. He really did miss Donnie. Leo would always find him in his lab, avoiding him but it was for a good reason. Donnie was embarrassed about his cycle and the eggs settled in his gut. He found it gross while Leo found it so sexy. The eldest smiled to his mate but Donnie was concerned.

"I..miss you too..but.."

"I know." Leo quickly said, "I just really miss you sleeping with me and just seeing you."

Donnie's cheeks turned a little red, a smile broke through his seriousness much to Leo's relief. "I haven't really slept well without you." Donnie admitted timidly. Donnie put the screwdriver down on the table, subconsciously, he ran his hand over his stomach and sighed. Leo shrugged. He took a few more steps closer to Donnie and grabbed his forearm. They really shouldn't be together like this. Leo's hormones were already sky rocketing and so were Donnie's. They didn't care. Leo leaned in and kissed Donnie's shoulder. His hand sunk down and grabbed his hand.

Their moment was short when Mikey and Raph came in. Leo broke his grip on Donnie's hand and walked away unwillingly. Damn it.

A few days had past without any interaction but it was better this way. This time it was Donnie feeling uncontrollably horny and frustrated beyond belief. His cock was painfully tucked in the pocket of his plastron, his slit dripping with cum as he resisted the urge to touch himself but it was pointless. He thought of Leo's musk, remembering his touch and the last time they had sex. If it wasn't for these stupid eggs he would let Leo bend him over and fuck him senseless. He reminded himself he wasn't an animal but now he really wasn't so sure. He jerked himself off while he placed one finger into his ass. It was tight and his finger was small compared to Leo's cock. Shell, he missed Leo so much.

Donnie finished himself off, a powerful orgasm wracked his body and thick strings of semen coated his swollen belly. He removed his finger and slumped back in his chair. If only that were the real thing.

"Ugh!" Donnie glared down at his belly before cleaning himself off. Even after masturbating he was still horny. He knew the only thing that would calm his body was his mate. It was in his natural to be fully and properly impregnated by Leo's seed. That's what he craved for. Donnie tossed the tissue into the bin and tucked his cock back into his slit with some difficulty. He was still hard- UGH!

He couldn't take it anymore. He gave up trying to put his cock in and grabbed and towel from the infirmary. He put it in front of his harden dick to avoid his brothers seeing his state and hurried to find Leo. He was glad to find him in his own room where they could get privacy.

Leo was mediating on the floor, he looked so peaceful and trance like that Donnie almost felt guilty for interrupting him. Almost. The creek of the door broke him from his trance.

"Don?" Leo looked up at him with a surprised look. Donnie entered, hastily closing the door and locking it firmly. He dropped the towel, letting Leo take a full look of his dripping sex with a extreme interest. "D..on.."

"Leo. I can't take it." Donnie dropped to his knees in front of him and began to rub his hand against Leo's slit. "Let's just do something, okay? I really need it. Please!"

"O-okay." Leo agreed. He was just trying to suppress these urges and now Donnie was begging him. He let Donnie rub him a bit more then dropped his cock into his awaiting hand. Leo moaned. "H-here." Leo stopped Donnie before he could continue. He laid down on his mat and beckoned for Donnie to come. Donnie positioned him facing Leo's cock while Leo faced Donnie's. This was their best solution. Leo took in Donnie's cock, sucking and licking at the wonderful bitter taste of cum. Donnie must have been jerking off earlier cause he could still taste the aftermath. He kept one hand holding Don's tail up, pressing his finger against the sensitive appendage just to feel Donnie's wiggle. Donnie was fantastic at giving head and was very eager. Leo's hips jerked up, thrusting into Don's mouth as he engulfed him. This was great.

The moment was halted, Donnie moved away and rolled of Leo.

"Get up." He demanded. His voice was deep and so enticing, Leo obeyed his mate.

"Fuck me, Leo." Donnie said firmly. He bent over on Leo's bed and moved his ass out. His hands went behind him to spread his ass out for Leo to see.

Leo's eyes widen. "Don. We can't!"

"Leo! Do it, please! Fuck me! I can't take it." Donnie pleaded. "I want you."

That was enough convincing for the sex starved turtle. Leo pushed Donnie's hands away and moved him in closer on the bed. Leo rubbed his cock against Donnie's ass, grinding and teasing him first to enjoy. Donnie's scent was strong once more, blasting his senses and telling him that Donnie needed to be bred. Donnie needed his cock. He pushed his way in slowly. Donnie hissed and grabbed the bed sheets. All logic was erased from his brain, he didn't care about anything but Leo's large cock filling his ass.

"Donnie.." Leo grunted. His cock slipped in deeper. He wasn't paying attention to Donnie's reaction, he knew it was painful but it would get better later. Donnie grind back against Leo, encouraging him on and didn't want him to stop. He purred, his body sensually curved in delight as Leo began to fuck him.

"O-oh! Leo, yes...oh god-" Donnie bit his lower lip, trying to keep down his moans but it was impossible. His body was yearning this for so long.

"You're so eager, Donnie." Leo panted, "You missed my cock, didn't you?"

"Oh god, yes!" The lanky turtle was squirming. "Fuck me, Leo, please!"

Leo sped up, drilling Donnie non-stop until the slap of their skin filled the room. They were both panting like dogs in heat. Leo held on to Donnie's hips, keeping him where he wanted him as he pounded into his tight ass. Donnie couldn't even bring out a coherent thought in his mind. Leo's thrusting died down but he certainly wasn't finished. He pulled out, tightly grabbing Donnie's ass and slapping his thigh, "On your back." He commanded.

Donnie rolled over on to his back, his legs spread open and waited patiently. Leo thrust back inside Donnie, making his mate cry out in surprise. Donnie was a hot mess in front of him, he could see his bright red blush and sweat pouring down his face and body. His belly was bouncing at each thrust. In this position, Donnie could feel the butterfly sensation in his belly and knew that the eggs were moving around. Leo was getting rough with him but he wasn't complaining at all. He hadn't had a proper fuck in for so long. Leo wrapped one arm around Donnie's body, pulling him closer and kissing his chest lovingly as he thrust in and out.

"You want me to cum inside you?" Leo asked lustfully. "Tell me how much you missed my cock, Donnie."

"I- ugGH! I missed it so much, please cum in me, Leo!" Donnie pleaded once more, "I need your seed to fill inside my belly, please give it to me.."

Leo kissed his chest again and moved his pace up a notch. Donnie was begging to be impregnated by his potent seed. Their bodies were locked together, ready and close. Donnie roughly grabbed Leo's face and kissed him fully on the lips. Their tongues clashed against one another, suckling and wildly kissing till they broke away to breath. Leo was so close, he felt so alert and animated to be finally giving Donnie his offering.

"Donnie!" Leo thrust in as far as he could and came. Donnie felt Leo's warm cum jet into his fertile belly, his womb hungrily ate up his mate's seed so that the eggs could have a chance at being fertilized. Never in Donnie's life had he ever felt so complete. A new sensation of warm blanketed him, it was such a safe and welcoming feeling.

"Nnghh..o-ohh.." Donnie muttered weakly. "Fuck.."

Leo waited until they were both relaxed and pulled out. He tucked himself back in then helped Donnie. He nuzzled the top of Donnie's belly with a large grin.

"I hate you soooo much."

Leo chuckled, "Why?"

"You know what this means, right?" Donnie fumed, "Leo, I'm so not ready for kids."

"Don't worry. What are the odds of it to happen just after one time?" Leo said cheekily. In the back of his mind was he sure of himself. The thought of Donnie baring his young, already growing strong and healthy made him feel proud. He nuzzled Don's belly again much to the other turtle's annoyance. "I love you, Donnie."

"I love you too."

_1 month later_

"Yup, definitely see at least three."

Leo stared happily at the small monitor with a wide smile. There they were, his little sons or daughters nestled up in Donnie's belly. The eggs that were fertilized had grown rapidly in such a short time. Donnie's stomach was much larger now thanks to the growing hatchlings soon to come.

"Move it here." Donnie moved to the side of his plastron, making sure that they hadn't missed anything. Leo ran the device over, changing the view of the screen. "Nope. Okay, just three. That's good."

"This is so exciting!" Leo said.

"Yeah. For you, I'm the one who has to carry them for 3 months." Donnie said bitterly. He was annoyed due to the weight, his back hurting and pretty much everything in between. He was happy, no mistaking it.

"How big do you think you'll get?"

"A few more inches then we have to check again to make sure it's just three. Ugh, help me up." Donnie held out his hands to his mate with a comical frown. Leo put down the device and helped his Donnie up. He kissed Donnie on his beak and nuzzled him.

"Do you think we should tell the others now?" Leo asked him.

Donnie smiled, "Let's wait a little more. Right now, I just want you." He pulled on Leo's belt to bring him back in for a kiss.


End file.
